HI.! In Electric Routing module when we route a harness Using Start by Drag/Drop Method (Please refer the below attached 2nd image) through clips. and after that if i want to create the 'FLATTEN ROUTE' the wires are coming in series way(as shown in the below attached 3rd image).
Actually it should come in parallel way showing that from which connector it starts and where it ends along with the wire length.
FYI i have attached a image(See the 1st image attached below) showing the Model Tree in which you will come to know how i have created the Harness and what are the components included in that.